Hitachi announced it agreed to purchase the Horizon nuclear power projects from German energy companies E.ON and RWE. The Japanese company said it aims to build as many as three plants, which could generate 1,000 megawatts of power each, at the site.
Hitachi President Hiroaki Nakanishi said the acquisition marks the start of a "100-year commitment" to the British energy sector.
The German energy companies in March announced they would end development work in the Horizon joint venture as part of a divestment strategy.
British Prime Minister David Cameron was quoted by the BBC as saying the $1.1 billion deal represented a major "vote of confidence in the U.K. that will contribute vital new infrastructure to power our economy."
On Monday, Russia's First Deputy Prime Minister Igor Shuvalov announced his interest in the British nuclear power sector.
"We discussed joint cooperation in some areas, including the construction of nuclear power plants. The Russian side is interested in such construction and commissioning of new plants here in Great Britain in cooperation with Rolls-Royce," he was quoted by state-run news agency RIA Novosti as saying.
The United Kingdom gets about 16 percent of its electricity from nuclear power.